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The structure of precursors is used to control the formation of six possible structural isomers that contain four structural units of PbSe and four structural units of NbSe2: [(PbSe)1.14]4[NbSe2]4, [(PbSe)1.14]3[NbSe2]3[(PbSe)1.14]1[NbSe2]1, [(PbSe)1.14]3[NbSe2]2[(PbSe)1.14]1[NbSe2]2, [(PbSe)1.14]2[NbSe2]3[(PbSe)1.14]2[NbSe2]1, [(PbSe)1.14]2[NbSe2]2[(PbSe)1.14]1[NbSe2]1[(PbSe)1.14]1[NbSe2]1, [(PbSe)1.14]2[NbSe2]1[(PbSe)1.14]1[NbSe2]2[(PbSe)1.14]1[NbSe2]1. The electrical properties of these compounds vary with the nanoarchitecture. For each pair of constituents, over 20 000 new compounds, each with a specific nanoarchitecture, are possible with the number of structural units equal to 10 or less. This provides opportunities to systematically correlate structure with properties and hence optimize performance.  相似文献   
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Subnanocatalysts (SNCs) containing various noble metals (Cu, Ru, Rh, Pd, or Pt) with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template. These materials exhibit high catalytic performance during toluene oxidation without the use of harmful solvents or explosive oxidants, resulting in the formation of valuable organic products, including benzoic acid as the major product. In particular, Pt19 SNC with a narrow particle size distribution exhibits extraordinary catalytic activity, with a turnover frequency of 3238 atom?1 h?1, which is 1700 times greater than that obtained by commercial Pt/C catalysts.  相似文献   
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We investigate the plasmonic response of gold nanospheres calculated using discrete dipole approximation validated against the results from other discretization methods, namely the finite-difference time-domain method and the finite-element methods. Comparisons are also made with calculations from analytical methods such as the Mie solution and the null-field method with discrete sources. We consider the nanoparticle interacting with the incident field both in free space and sitting on a planar substrate. In the latter case, discrete dipole approximation with surface interaction is used; this includes the interaction with the ‘image dipoles’ using Sommerfeld integration.  相似文献   
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Small amounts of multicrystalline silicon were melted in an electron beam furnace in different experimental conditions in order to investigate the oxygen evaporation behavior during the electron beam melting (EBM) process. The oxygen content level before and after EBM was determined by secondary ion mass spectroscopy. The oxygen content was reduced from 6.177 to 1.629 ppmw when silicon was melted completely at 15 kW with removal efficiency up to 73.6 %. After that, it decreased continually to <0.0517 ppmw when the refining time exceeded 600 s with a removal efficiency of more than 99.08 %. During the melting process, the evaporation rate of silicon is 1.10 × 10?5 kg/s. The loss of silicon could be reduced up to 1.7 % during oxygen removal process to a desirable figure, indicating EBM is an effective method to remove oxygen from silicon and decrease the loss of silicon.  相似文献   
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This paper presents the analysis of circular ring metamaterial absorber with the existing of copper lines. The structure is designed using lossy FR4 substrate with thin copper layers. The circular ring shape with copper lines is printed on the top surface of FR4 substrate, while at the bottom surface is printed with full copper ground plane. Parametric study is done to investigate the effect of copper lines on the resonance frequency. From the simulation, the circular ring metamaterial absorber with vertical copper lines can resonates at lower frequency, but this structure is polarized sensitive. This drawback can be improved by adding horizontal copper lines together with the vertical copper lines. The circular ring structure with vertical and horizontal copper lines is not only polarization insensitive, but it can works at wide operating angle of incident waves.  相似文献   
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